Behavioral and cognitive interventions will be used to improve compliance to diet and exercise regimens among patients with noninsulin-dependent type II diabetes mellitus. In the first experiment, cognitive and behavioral interventions will be varied in a 2 X 2 factorial design. Patients will be randomly assigned to one of four conditions: 1) cognitive only, 2) behavioral only, 3) cognitive plus behavioral, or 4) attention control. This experiment will identify the most effective intervention for changing behavior patterns in this patient group. The most successful intervention will be used in a second experiment in an attempt to increase compliace to either 1) a dietary program, 2) an exercise program, or 3) a program which combines diet and exercise. These groups will be compared against a control group which receives an education program but no special compliance training. A Health Status Index will be used to assess the effect of interventions on quality of life and for cost-benefit analysis. Biochemical studies of compliance will be performed by analyzing glycosylated hemoglobins. In addition, a variety of other outcome measures will be used including exercise tolerance and personal expectancy for change. Each patient will be followed at regular intervals for 18 months. A variety of multivariate studies will be performed using the data set. The data will be interpreted in terms of self efficacy theory.